I have an object of newsfeed items like below.

[{'story_id':130,'pinned':0,....},{'story_id':131,'pinned':1,....},{'story_id':132,'pinned':0,....},{'story_id':133,'pinned':0,....}]

I need to primarily order the news stories by their story_id DESC. But if a story has the property 'pinned'=1 it needs to be first.

filtered_news_feed: function() {
    var list= _.orderBy(this.feed_items, ['story_id'],'desc');
    return list;
},

The above works, but how do I do pinned items first, then the rest? For some reason the below completely ignores the story_id

var list= _.orderBy(this.feed_items, ['pinned','story_id'],'desc');

CodePudding user response：

Using Array#sort:

const arr = [ {'story_id':130,'pinned':0}, {'story_id':131,'pinned':1}, {'story_id':132,'pinned':0}, {'story_id':133,'pinned':0} ];

const sorted = arr.sort(
  ({ story_id: storyIdA, pinned: pinnedA }, { story_id: storyIdB, pinned: pinnedB }) => 
    pinnedB - pinnedA || storyIdB - storyIdA
);

console.log(sorted);

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

You can achieve this results in many ways, one of them is:

filtered_news_feed: function() {
  const pinnedItems = this.feed_items.filter(item => item.pinned === 1);
  const normalItems = this.feed_items.filter(item => item.pinned === 0);

  return [
     ...pinnedItems,
     _.orderBy(normalItems, ['story_id'], 'desc')
  ];
}

First, separate pinned items from normal items. Then return merged array with pinned items at the beginning.

Note: I used modern features of ES here. You should compile it via babel or other tool.